Thermo-setting resinous liquid compositions

ABSTRACT

A liquid composition comprising a dispersion of silica colloid in alcohol and a thermo-setting resin. The dry film of this composition is superior in chemical resistance, surface hardness, abrasion resistance, heat resistance and adhesiveness to a substrate.

BACKGROUND OF THE INVENTION

The present invention relates to a liquid composition comprising a dispersion of silica colloid in alcohol and a thermo-setting resin.

Compositions compounded with large quantities of inorganic substances such as calcium carbonate, clay, talc, mica, etc., as fillers are widely known. However, these fillers may rather be said to have been mixed merely for the purpose of reducing the cost.

The liquid composition of the present invention, which comprises a mixture of a dispersion of silica colloid in alcohol and a thermo-setting resin, has been found to exhibit, when hardened at room temperature or by heating, an excellent efficiency utterly different from the conventional thermo-setting resin compositions compounded with inorganic fillers. In other words, the film made from the liquid composition of the present invention has been found to exhibit improved properties such as chemical resistance, surface hardness, abrasion resistance, adhesiveness, heat resistance, etc. These improved properties are considered attributable to the formation of a composite comprising an active silanol on the surfaces of silica fine particles and a thermo-setting resin.

SUMMARY OF THE INVENTION

The present invention provides a liquid composition comprising a dispersion of silica colloid in alcohol and a thermosetting resin. The solid content of this liquid composition preferably comprises 1 to 80 wt.% of silica and 99 to 20 wt.% of a thermo-setting resin.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As the thermo-setting referred to in the present invention there may be used any polymer containing, in the polymer chain and/or terminal, at least one of a hydroxyl group (including a phenol type hydroxyl group and its alkylether group), a carboxyl group, an epoxy group, an amino group, an acid anhydride group (--CO--O--OC--), an isocyanate group and a silanol group. In the concrete, as the thermo-setting resin there can be enumerated acrylic, acryl-melamine, acryl-epoxy, acryl-urethane, melamine-alkyd, epoxy, epoxy-phenolic, phenolic or silicone resin. These resins are easy to obtain commercially.

The dispersion of silica colloid in alcohol used in the present invention is prepared by using a lower alcohol as the dispersion medium an aqueous silica sol in place of water. This aqueous silica sol is a stable colloidal liquid wherein gelation of colloid has been prevented by the steps of producing silica colloid by neutralizing a dilute aqueous solution of sodium silicate with an acid, then growing colloidal particles to have a diameter of 10 to 50 mμ while condensing the liquid and thereafter controlling the pH of the liquid. The aqueous silica sols of this sort are commercially available in the trade names, for instance, Cataloid (a produced of Catalysts & Chemicals Industries Co., Ltd.), Snowtex (a product of Nissan Kogaku Kogyo K.K.), Ludox (a product of Du Pont Co.), etc.

The substitution of the dispersion medium can be effected by adding the lower alcohol to the aqueous silica sol and distilling water out by means of distillation or the like. The lower alcohol used herein includes methanol, ethanol, propanol and butanol. The silica concentration of the alcohol dispersion may be selected optionally, but preferably is in the range of 1 to 50 wt.%.

As the aqueous silica sol is a water dispersion, its usage has usually been restricted to the so-called water system, for instance, such as prevention of sliding for paper articles, shell molds for precision metal casting, inorganic binders for various refractory bodies, adhesion improver and reinforcing agent for latex coating, etc. In contrast, the present invention uses the silica colloid in the form of an alcohol dispersion and thus permits the formation a composite comprising the silica colloid and the thermo-setting resin. Due to this, the hardened product of this liquid composition can exhibit exceedingly improved chemical resistance, surface hardness, abrasion resistance, adhesiveness, and heat resistance.

The liquid composition of the present invention is further added with a filler, a coloring agent and various additives, and thus can be used for various purposes, for instance, such as primers, coating, lining, inking, adhesives, sealing agents, casting or various treating agents and impregnant.

Hereinafter, the present invention will be explained more concretely with reference to examples.

EXAMPLE 1

A dispersion of the silica colloid in isopropyl alcohol (N.V.=30%, which will be referred to IPA-silica hereinafter) was added to melamine-alkyd resin [Beckosol J-541-50: a product of Dainippon Ink and Chemicals, Inc.]. The resulting mixture was applied onto a degreased, cold rolled steel sheet (SPCC-SD), and same was baked at 120° C. for 20 minutes. The physical properties of the coating film thus obtained are as shown in Table 1.

                                      TABLE 1                                      __________________________________________________________________________                    Appearance                                                                            Resistance to.sup.(b)                                       Silica.sup.(a)                                                                      Appearance                                                                            of coating                                                                            methylene                                                                              Pencil                                           No.                                                                               (wt. %)                                                                             of mixture                                                                            film   chloride                                                                               hardness                                                                            Adhesiveness.sup.(c)                        __________________________________________________________________________     1   0   transparent                                                                           colorless,                                                                            failed in the                                                                          3H   100/100                                             solution                                                                              transparent                                                                           first test                                               2  29   transparent                                                                           colorless,                                                                            failed in the                                                                          5H   "                                                   solution                                                                              transparent                                                                           7th test                                                 3  38   transparent                                                                           colorless,                                                                            passed 10 tests                                                                        6H   "                                                   solution                                                                              transparent                                                     4  44   transparent                                                                           colorless,                                                                            passed 10 tests                                                                        6H   "                                                   solution                                                                              transparent                                                     __________________________________________________________________________      .sup.(a) Silica content (wt. %) of the final solid coating film.               .sup.(b) Spot test.                                                            .sup.(c) Adhesiveness: Checkerboard test.                                

EXAMPLE 2

The exactly same tests as Example 1 were repeated except that IPA-silica was added to an oil-free type melamine-alkyd resin (Beckliht M-6003-60: a product of Dainippon Ink and Chemicals, Inc.) and the resulting mixture was baked at 110° C. for 30 minutes. The obtained results are as shown in Table 2.

                                      TABLE 2                                      __________________________________________________________________________                    Appearance                                                                            Resistance                                                  Silica                                                                              Appearance                                                                            of coating                                                                            to methyl                                                                             Pencil                                            No.                                                                               (wt. %)                                                                             of mixture                                                                            film   ethyl ketone                                                                          hardness                                                                            Adhesiveness                                 __________________________________________________________________________     1   0   transparent                                                                           transparent                                                                           failed in the                                                                         F    100/100                                              solution      first test                                               2  30   transparent                                                                           slightly                                                                              failed in the                                                                         H    "                                                    solution                                                                              milky  6th test                                                 3  40   transparent                                                                           slightly                                                                              failed in the                                                                         2H   "                                                    solution                                                                              milky  6th test                                                 __________________________________________________________________________

EXAMPLE 3

The exactly same tests as Example 1 were repeated except that IPA-silica was added to an acrylmelamine resin (Aclose #6000 Clear, NV=50%: a product of Dai Nippon Toryo Co., Ltd.) and the resulting mixture was baked at 150° C. for 20 minutes. The obtained results are as shown in Table 3.

                                      TABLE 3                                      __________________________________________________________________________             Appearance                                                                            Resistance                                                         Silica                                                                              of coating                                                                            to Methyl-                                                                            Pencil                                                   No.                                                                               (wt. %)                                                                             film   ene chloride                                                                          hardness                                                                            Adhesiveness                                                                          Abrasion.sup.(a) (mg)                        __________________________________________________________________________     1   0   transparent                                                                           failed in the                                                                         2H   100/100                                                                               11.4                                                        first test                                                      2  30   "      failed in the                                                                         5H   "      2.9                                                         8th test                                                        3  40   slightly                                                                              failed in the                                                                         6H   "      2.8                                                  milky  8th test                                                        __________________________________________________________________________      .sup.(a) Abrasion wear: Determined by a usual method with a Taber machine      under conditions comprising a load of 500 g, rotation rate of 200 and          truck wheel CS17.                                                        

EXAMPLE 4

IPA-silica was added to an acryl-epoxy resin (main component: acrylic resin, hardening agent: epoxy resin, mixing ratio of the main component to the hardening agent=10/1 by weight: a product of Ohashi Chemical Industries Co., Ltd.). The resulting mixture was applied onto a degreased polymethyl methacrylate plate (PMMA) and sheet-molding compound plate (SMC) and same was baked at 80° C. for 30 minutes. The physical properties of the coating film thus obtained are as shown in Table 4.

                                      TABLE 4                                      __________________________________________________________________________             Appearance                                                                Silica                                                                              of coating                                                                            Resistance                                                                           Pencil                                                                              Adhesiveness.sup.(a)                                                                   Adhesiveness.sup.(b)                         No.                                                                               (wt. %)                                                                             film   to toluene                                                                           hardness                                                                            (a)     (b)                                          __________________________________________________________________________     1   0   transparent                                                                           failed in the                                                                        2H   100/100  20/100                                                     first test                                                      2  35   "      passed the                                                                           4H   "       100/100                                                     tenth test                                                      3  47   "      passed the                                                                           5H   "       "                                                           tenth test                                                      4  52   "      passed the                                                                           5H   "       "                                                           tenth test                                                      __________________________________________________________________________      .sup.(a) Adhesiveness (a): Adhered PMMA                                        .sup.(b) Adhesiveness (b): Adhered SMC                                   

EXAMPLE 5

IPA-silica was added to an acryl-urethane resin (main component: Orester Q602, hardening agent: Orester P49-75S: a product of Mitsui Toatsu Chemicals, Inc.). The resulting mixture was applied onto a degreased PMMA plate and same was baked at 80° C. for 30 minutes. The physical properties of the coating film thus obtained are as shown in Table 5.

                  TABLE 5                                                          ______________________________________                                              Silica  Appearance           Pencil                                            (wt.    of coating  Resistance                                                                              hard- Adhe-                                  No.  %)      film        to toluene                                                                              ness  siveness                               ______________________________________                                         1     0      transparent failed in the                                                                            H    100/100                                                         first test                                            2    34      "           failed in the                                                                           3H    "                                                               5th test                                              3    46      "           failed in the                                                                           4H    "                                                               8th test                                              4    51      "           passed the                                                                              4H    "                                                               10th test                                             ______________________________________                                    

EXAMPLE 6

IPA-silica was added to 100% acrylic resin (Duracron CW Clear: a product of Dai Nippon Toryo Co., Ltd.). The resulting mixture was applied onto a degreased aluminum plate and same was baked at 180° C. for 30 minutes. The physical properties of the coating film thus obtained are as shown in Table 6.

                  TABLE 6                                                          ______________________________________                                                                           Pencil                                            Silica   Appearance of                                                                              Resistance                                                                             hard- Adhe-                                  No.  (wt. %)  coating film                                                                               to toluene                                                                             ness  siveness                               ______________________________________                                         1     0       transparent passed the                                                                             2H    100/100                                                          tenth test                                           2    10       "           passed the                                                                             3H    "                                                                tenth test                                           3    20       "           passed the                                                                             3H    "                                                                tenth test                                           4    30       "           passed the                                                                             3H    "                                                                tenth test                                           ______________________________________                                    

EXAMPLE 7

IPA-silica was added to an epoxy resin (Eponics #1100 Clear: a product of Dai Nippon Toryo Co., Ltd.). The resulting mixture was applied onto a degreased, cold rolled steel sheet and same was baked at 180° C. for 30 minutes. The physical properties of the coating film thus obtained are as shown in Table 7.

                                      TABLE 7                                      __________________________________________________________________________        Silica                                                                              Appearance of                                                                          Resistance to                                                                            Pencil                                                                              Adhesive-                                                                            Abrasion.sup.(a)                          No.                                                                               (wt. %)                                                                             coating film                                                                           methylene chloride                                                                       hardness                                                                            ness  wear (mg)                                 __________________________________________________________________________     1   0   transparent                                                                            passed the tenth                                                                         5H   100/100                                                                              2.2                                                       test                                                           2  20   "       passed the tenth                                                                         6H   "     0.8                                                       test                                                           3  30   "       passed the tenth                                                                         7H   "     --                                                        test                                                           4  40   "       passed the tenth                                                                         9H   "     0.8                                                       test                                                           __________________________________________________________________________      .sup.(a) Abrasion wear: Load: 500 g, rotation: 200, truck wheel CS17.    

EXAMPLE 8

IPA-silica was added to a phenolic resin (a product of Dai Nippon Ink and Chemicalsl, Inc.). The resulting mixture was applied onto a degreased, cold rolled steel sheet and same was baked at 190° to 200° C. for 30 minutes. The physical properties of the coating film thus obtained are as shown in Table 8.

                                      TABLE 8                                      __________________________________________________________________________                          Resistance                                                   Phenolic                                                                            Silica                                                                              Appearance of                                                                          to methylene                                                                          Pencil                                                                              Adhesive-                                                                            Abrasion.sup.(a)                        No.                                                                               resin                                                                               (wt. %)                                                                             coating film                                                                           chloride                                                                              hardness                                                                            ness  wear (mg)                               __________________________________________________________________________     1        0   brown,  passed the                                                                            6H   100/100                                                                              --                                                   transparent                                                                            tenth test                                                2  Plyophen                                                                            20   light brown,                                                                           passed the                                                                            7H   "     --                                         5010      transparent                                                                            tenth test                                                3       40   light brown,                                                                           passed the                                                                            8H   "     --                                                   transparent                                                                            tenth test                                                4        0   brown, trans-                                                                          passed the                                                                            7H   "     12.2                                                 parent  tenth test                                                5  Plyophen                                                                            20   light brown,                                                                           passed the                                                                            8H   "     --                                         TD 447    transparent                                                                            tenth test                                                6       40   light brown,                                                                           passed the                                                                            9H   "     9.5                                                  transparent                                                                            tenth test                                                __________________________________________________________________________      .sup.(a) Abrasion wear: 500 g load, 1000 rotations, truck wheel CS17.    

EXAMPLE 9

IPA-silica was added to an epoxy-phenolic resin, and then the same test as used in Example 8 was repeated thereon. The obtained results are as shown in Table 9, wherein as the epoxy-phenolic resin there were used 20 parts of "Plyophen TD447" and 20 parts of "Epikot 1007" (a product of Shell Chemical Co.) diluted with methyl isobutyl ketone.

                  TABLE 9                                                          ______________________________________                                                       Appearance Resistance to                                                                           Pencil                                            Silica   of coating film                                                                           methylene                                                                               hard- Adhe-                                  No.  (wt. %)  film       chloride ness  siveness                               ______________________________________                                         1     0       transparent                                                                               passed the                                                                              3H    100/100                                                         tenth test                                            2    10       "          passed the                                                                              4H    "                                                               tenth test                                            3    20       "          passed the                                                                              4H    "                                                               tenth test                                            4    40       slightly   passed the                                                                              4H    "                                                    milky      tenth test                                            ______________________________________                                    

EXAMPLE 10

IPA-silica was added to a silicone resin. The resulting mixture was applied onto a degreased glass plate and same was baked at 180° C. for 60 minutes. The physical properties of the coating film thus obtained are as shown in Table 10.

                                      TABLE 10                                     __________________________________________________________________________               Silica  Appearance of                                                                          Resistance to                                                                         Pencil                                                                              Adhesive-                                No.                                                                               Silicon resin                                                                         content (wt. %)                                                                        coating film                                                                           toluene                                                                               hardness                                                                            ness                                     __________________________________________________________________________     1  Tore    0      transparent                                                                            failed in the                                                                         B    50/100                                      silicone               first test                                              SH 806.sup.(a)                                                              2         10      slightly                                                                               failed in the                                                                         F    100/100                                                    milky   third test                                           3         20      milky   failed in the                                                                         F    "                                                                  third test                                           4  Tore    0      transparent                                                                            adhesive                                                                              B     0/100                                      silicone       and crack                                                       SH 6018.sup.(b)                                                                               observed                                                     5         10      slightly                                                                               slightly                                                                              F    80/100                                                     milky   adhesive                                             6         20      slightly                                                                               slightly                                                                              F    50/100                                                     milky and                                                                              adhesive                                                               crack observed                                               __________________________________________________________________________      .sup.(a) NV = 50% Solvent: toluene/xylene                                      .sup.(b) Powder solid, Mean molecular weight = 1600 (The powder solid was      used in the manner of diluting it with diacetone alcohol so that NV is         equal to 50%.)                                                            

We claim:
 1. An essentially water-free liquid composition comprising a composite formed from (a) an essntially water-free dispersion of silica colloid in alcohol, said silica having particle diameter of between about 10 and 50 mμ, and (b) a thermo-setting resin selected from the group consisting of acrylic, acryl-melamine, acryl-epoxy, acryl-urethane, melamine-alkyd, epoxy, epoxy-phenolic, phenolic and silicone resins.
 2. A liquid composition according to claim 1 wherein the quantity of said silica present in the solid content of said composition is 1 to 80 wt.% and the quantity of said thermosetting resin present therein is 99 to 20 wt.%. 